内容正文:
2019-2020 学年度第一学期期中学业水平检测
高一物理答案及评分标准
一、选择题:本大题共 12 小题,每小题 4 分,共 48 分。
二、填空:本大题共 2 小题,共 12 分。
13.(6 分)(1) ①③(2 分);(2)0.263(2 分),0.505(2 分);
14.(6 分)(1) 25.83(25.81-25.85)(2 分);(2)0.98(2 分),(3)AD(2 分)。
三、解答题:本大题共 4 小题,共 40 分,解答时应写出必要的文字说明、证明过程或演算步骤。
15.(8 分)
(1)解:由 v-t 图象与时间轴围成图形的面积在数值等于位移的大小,并且时间轴上方的位移为正,时间
轴下方的位移为负,所以 0~6s 内的位移为:
( )1 12 5 10 1 10 30m
2 2
s m m= × + × − × × = ···································································· (4 分)
(2)v-t 由图象可知,5s 末时离出发点最远,最远距离为:
( )max
1 2 5 10 35m
2
s m= × + × = ················································································· (4 分)
16.(9 分)
解:(1)当 F1=30N 时,物体做匀速直线运动,根据平衡条件有: 1 1F f=
又 1f N mgm m= = ································································································ (2 分)
解得: 1= 0.2f
mg
m = ······························································································ (1 分)
(2)由题意,因 2 max =30NF f< ,即物体在 20N 的拉力作用下处于静止状态 ··················· (1 分)
根据平衡条件得:f2=20N ······················································································· (2 分)
(3)因 3 max =30NF f> ,即物体在 50N 的拉力作用下处于匀加速运动 ································ (1 分)
则物体一直受滑动摩擦力,有: 3 1 30Nf f= = ··························································· (2 分)
题号 1 2 3 4 5 6 7 8 9 10 11 12
答案 A C B A C C B C AB BC BC BCD
高一物理答案 第 1 页(共 2 页)
17.(11 分)
解:(1)对汽车,由 2 20
1 110
2 4
x v t at t t= + = −
知初速度 v0=10m/s,加速度 a=-0.5m/s2,做匀减速直线运动;
对自行车,x=vt=4t,以 4m/s 的速度做匀速直线运动 ···················································· (1 分)
自行车与汽车共速的时间 1 01
4 10 s 12s
0.5
v vt
a
− −
= = =
−
此时汽车的位移 0 11 1
+ 10 4 12 84m
2 2
v vx t += = × = ························································· (2 分)
自行车的位移 x2=vt=48m ······················································································· (1 分)
故相距最远Δx=x1-x2=36m ······················································································· (1 分)
(2) 汽车速度减为零的时间 02
0 10 s 20s
0.5